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Accession Number
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N20120011817
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Title
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Group Increment Scheme for Infrared Absorption Intensities of Greenhouse Gases.
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Publication Date
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Mar 2012
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Media Count
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24p
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Personal Author
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J. S. Francisco P. P. Bera S. I. Kokkila T. J. Lee
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Abstract
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A molecule's absorption in the atmospheric infrared (IR) window (IRW) is an indicator of its efficiency as a greenhouse gas. A model for estimating the absorption of a fluorinated molecule within the IRW was developed to assess its radiative impact. This model will be useful in comparing different hydrofluorocarbons and hydrofluoroethers contribution to global warming. The absorption of radiation by greenhouse gases, in particular hydrofluoroethers and hydrofluorocarbons, was investigated using ab initio quantum mechanical methods. Least squares regression techniques were used to create a model based on this data. The placement and number of fluorines in the molecule were found to affect the absorption in the IR window and were incorporated into the model. Several group increment models are discussed. An additive model based on one-carbon groups is found to work satisfactorily in predicting the ab initio calculated vibrational intensities.
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Keywords
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Additives
Global warming
Greenhouse effect
Histograms
Infrared absorption
Infrared windows
Least squares method
Mathematical models
Quantum chemistry
Regression analysis
Vibrational spectra
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Source Agency
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National Aeronautics and Space Administration
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NTIS Subject Category
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68A - Air Pollution & Control
55E - Physical Meteorology
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Corporate Author
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National Aeronautics and Space Administration, Moffett Field, CA. Ames Research Center.
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Document Type
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Journal article
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Title Note
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N/A
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NTIS Issue Number
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1226
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Contract Number
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N/A
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